The present invention relates to a display apparatus of a hold type represented by a Thin Film Transistor (TFT) liquid crystal display and more particularly to a display apparatus which can realize improvement in the picture quality at the time that dynamic picture is displayed.
Active matrix type display apparatuses such as TFT liquid crystal displays have features of thin structure, high definition and low power consumption and accordingly are utilized widely as display apparatuses in mobile apparatuses such as mobile telephones and mobile information terminals. Particularly, the mobile telephones have increased cases in which dynamic picture is used in one-segment broadcasting, reproduction of recorded dynamic picture and applications containing games with the advance of high functions. However, the TFT liquid crystal displays are of hold-type driving in which the same image is continuously displayed during one frame period and accordingly when the dynamic picture is displayed, the picture remains in the eyes as an afterimage and there occurs the phenomenon that the outline of the displayed image is blurred (hereinafter as “blurring of dynamic picture”).
As measures to prevent deterioration in the picture quality generated in such hold-type display apparatuses, U.S. Pat. No. 6,473,077 (JP-A-2000-122596) proposes a system in which the period that black is displayed is inserted during one frame period so that the afterimage in the eyes is canceled to improve the blurring of dynamic picture. However, the system of inserting black to attain the impulse type driving as represented by a cathode ray tube (CRT) spuriously reduces the maximum brightness and the contrast of displayed image.
On the other hand, U.S. Patent Application Serial No. 20050253785 (JP-A-2005-173387) proposes a system in which one frame is divided into some sub-frames to compensate the brightness reduced by insertion of black by other sub-frames as in the spurious impulse type driving but reduction in brightness and contrast is prevented when estimated during one frame period. The system requires to prepare low-brightness sub-frame data for the spurious impulse type driving and high-brightness sub-frame data for compensation of brightness on the basis of one frame data inputted to the system, although a look-up table (hereinafter referred to as “LUT”) is used to perform data conversion processing at this time. This system is hereinafter referred to as “LUT system”. In order to realize such LUT system, a memory having a large capacity is required as the LUT for storing converted data, although since a circuit area is increased when it is provided in the hardware such as LSI, not only the cost is increased but also it is difficult to apply it to mobile apparatuses having strict restriction on the circuit area.
Further, active matrix type display apparatuses such as liquid crystal display apparatuses have features of thin structure, high definition and low power consumption and accordingly are utilized widely as display apparatuses in mobile apparatuses such as mobile telephones and mobile information terminals. Particularly, the mobile telephones have increased cases in which dynamic picture is used in one-segment broadcasting, reproduction of recorded dynamic picture and applications containing games with the advance of high functions. When such dynamic picture is displayed, the contrast is improved to attain high-grade picture.
For such improvement of the contrast, U.S. Patent Application Serial No. 20070188623 (JP-A-2006-24176) discloses that a look-up table (LUT) is used to emphasize the contrast.